A. Field of the Invention
The present invention relates to pre-installation, precise preliminary aiming of devices to pre-designed orientations, and then efficient and precise installation with precise final aiming, and in particular, to a comprehensive system of preliminary aiming and then installation, and also to specific apparatuses and methodologies that can be used in parts or components of the comprehensive systems.
B. Problems in the Art
A variety of devices exist that need to be installed in relatively precise pre-determined orientation(s) or directions. One example is wireless communications tower devices such as are found on cellular telephone, land mobile radio, or television towers. Normally the transmitter(s) or receiver(s) are installed in pre-planned geographical direction(s) for best signal coverage for a given geographic area. Another example is airport runway towers. The orientation of such lights must be directional and unequivocal to help pilots locate and guide the plane to the runway. A further example is lighting fixtures. Arrays of lighting fixtures are suspended on tall poles. Each fixture is individually oriented in reference to certain unique points on or near the field or target to be lighted. The orientations of each fixture are many times pre-determined to attempt to meet intensity and uniformity minimums across the field or target.
One way to aim or orient such device(s) to its/their desired installed position is to erect the supporting structure and then elevate a worker to the device(s). Each device is then manually adjusted to some approximate orientation by the elevated worker. Alternatively, some method can be devised to find or measure relative to the predetermined orientation. In any event, it is usually difficult for one worker to adjust, aim, and then lock in correct orientation relatively large and cumbersome devices when elevated high in the air or when standing high on a tower. This is especially true if outdoors. Wind, precipitation, or other outside environment factors can make this work very difficult. Even with two or more workers, it is still difficult to adjust, aim and lock in the correct orientation from these high elevations. Additionally, the precise orientation of the devices is difficult to achieve with tools and methods commonly available to field workers.
In the example of sports lighting systems, if the poles and fixtures are erected and then aimed, one or more workers must be elevated high up in the air in difficult working conditions and try to communicate with persons on the ground who would direct the aiming of each fixture. This would use up substantial amounts of time and labor. It usually would require much trial and error. Human error enters into these methods. It is quite difficult to visually identify the center of a beam with the human eye from hundreds of feet, even if attempted at night with the beam projected onto the field. If windy or otherwise unfavorable environmental conditions exist, it is quite difficult for the worker up at the fixtures to be accurate. The mere fact that a crane or other elevating system must be used for substantial periods of time (and thus taken away from other productive use) is quite inefficient and costly.
To reduce field installation time and improve the accuracy of the device orientation or aiming, a preliminary orientation may be set by the manufacturer prior to shipment. This is generally a good practice since the manufacturer or designer of the system understands the needs of the device aiming better than the installation crew. However, accurate preliminary aiming at the manufacturer or assembler can be challenging. Any errors introduced during assembly are often compounded by additional errors during installation. In addition, variances in manufacturing process, personnel and components can also interject errors in the device orientation.
In these examples, accuracy of the final installed aiming can be very important, if not critical. Take the case of a system of lighting fixtures elevated to substantial heights and aimed to specifically predetermined aiming points in the area to be illuminated. One reason to do so is to place light in specific locations. Still further, this can be important when the lighting system includes multiple fixtures. Instead of random or rough aiming of fixtures to achieve lighting of the target area, efficient utilization of light, as well as better uniformity and intensity levels, can be accomplished according to a predesigned plan of aiming each fixture to aiming points in the target area. With recent technological advances in the lighting efficiency from sports lighting fixtures, for example those manufactured by Musco Sports Lighting, LLC of Oskaloosa, Iowa, USA, the precise orientation of the fixtures is desirable to ensure the light is directed to the intended location. Tighter control of the light beam helps reduce wasted light and spill light off the target area. However, it also requires the installation and orientation of the lights to be more exact.
The concept of a pre-designed fixture aiming plan is well known in the sports lighting field. The lighting system must meet minimum intensity and uniformity requirements for the target area. One example is lighting for an athletic field. Computer programs are available and widely used to compute the number of lighting fixtures and their aiming orientation to the target area based on pole locations and light output characteristics from the lighting fixtures. By referring, for example, to FIG. 17 and issued U.S. Pat. No. 7,500,764 entitled “Method, Apparatus, and System of Aiming Lighting Fixtures” and related U.S. application Ser. Nos. 12/270,098, now U.S. Pat. No. 7,918,586, and 12/323,838, now U.S. Pat. No. 8,104,925, each of which is incorporated by reference herein, diagrammatic illustrations of a concept of different angular aiming orientations for multiple fixtures elevated on poles relative to a sports field are shown. There is a need to cover the entire field in a comprehensive and uniform manner. Most times each fixture is aimed to a unique point on the field.
By choice or necessity, many times lighting fixtures are elevated to substantial heights (e.g. from 35 to 150 feet). Also they may be elevated on poles which are offset from the target area such that the distances from each fixture to its aiming location on the field are substantial, even up to hundreds of feet. It can be appreciated, and is well known in the art, that accurate placement of the center of a light beam from a lighting fixture at these great distances from the aiming point is not trivial. In fact, it is quite difficult. Furthermore, any misalignment from the aiming point of even a few degrees (or even less) vertically or horizontally can shift the beam from its intended projection onto the field significantly. Geometrically, a few degrees of offset at the top of a pole hundreds of feet away can shift the beam center quite a few feet. For example, a fixture elevated at 100 feet and aimed 60 degrees from nadir can be off its target aiming point by over 7 feet when the vertical aiming orientation is off by a mere 1 degree (61 degrees from nadir). Thus, such variances from exact aiming accuracy can upset the composite lighting of the target area enough that it would potentially negatively impact intensity and uniformity requirements for such a field.
These types of concerns have been discussed in co-owned issued U.S. Pat. No. 7,500,764 and related U.S. application Ser. Nos. 12/270,098, now U.S. Pat. No. 7,918,586, and 12/323,838, now U.S. Pat. No. 8,104,925. Not only is it difficult to get precise aiming of lighting fixtures that are attached to cross arms on poles, the methodology of aiming is cumbersome and can be quite inefficient from a resource standpoint. U.S. Pat. No. 7,500,764 and the related applications cited above describe an aiming method having advantages over other methods which rely on aiming fixtures once the pole(s) are erected by elevating a worker to do so. It places a relatively inexpensive collimated light source, such as alignment beam pointer or device, on at least one light fixture on each pole or array of lighting fixtures for the field or target. Each fixture of the pole or array is pre-aimed either on the ground or at the factory. The pole and/or array are then simply pivoted to vertical at the appropriate location for the pole and the alignment beam turned on. If it intersects with the correct aiming point on the target area for that fixture (each fixture has its own designed aiming point on the field that is determined by a lighting layout design), it is assumed each other pre-aimed fixture of the pole or whole array is also correctly aimed since the array is essentially a collective group of devices mounted together on a framework that allows the group to act as a composite unit. However, this assumption may interject substantial error into the lighting design. If the fixture with the alignment beam is incorrectly aimed, even a few degrees of error (or less) could materially disrupt the composite lighting of the field, because it would then be likely that all fixtures on that pole would also end up miss-aimed. Error could exist by human error in aiming the fixture with the alignment beam. Or it could exist because of manufacturing tolerances. For example, the cross-arm on which the fixture is mounted may be warped, or there may be manufacturing error or play in the connection between the fixture and the cross-arm. This method also requires a fairly accurate mount of the alignment beam to the fixture so that it at least coincides with a reference, e.g. vertical plane through the aiming axis of the fixture. If not correctly mounted, the assumption the alignment beam is an accurate reference can interject substantial error into the installation. This method also requires workers to accurately find the appropriate aiming point on the field or target for the alignment beam. This interjects substantial risk of human error into the process. It can be difficult to accurately locate a point on a large area such as an athletic field that is many hundreds of feet in length and width. It is difficult to be precise with a measuring tape of those lengths. Thus, even if this method avoids individual aiming of fixtures after elevated on their poles, there are a number of factors that can interject material error into the installation.
Another aspect of aimed devices is the accuracy of the installation of the support structure the devices are mounted to. Examples are poles, towers, and other tall structures. Many times these tall structures are assembled on the ground and must be raised into vertical position and then precisely lowered onto a support base. For example, the base can be a protruding structure that the pole slip mates over or more of an in-ground footing to which the pole could be attached by anchor bolts. Control of the structure alignment during installation is critical to the accuracy of the aimed devices. Often times, the structure (e.g. pole with light fixtures, tower with wireless transceivers, etc.) is held free by the crane to allow the worker to align the structure as needed to achieve the desired orientation of the aimed devices. However, as the structure is lowered to its final position, the worker would benefit from micro level or fine control over the structure rotation to reduce risk of slight movement or misalignment of the structure that can occur due to lack of control by the worker. A method of controlling the structure orientation during installation is needed and solved by this invention.
Therefore, there is a need in the art for improvements in accurate aiming of lighting fixtures that are elevated on poles or other structures designed for a specific accurate angular orientation to target area aiming points. There is also a need in the art of improvement in accurate aiming of other devices that are elevated or supported on structures to substantial heights.
Definitions
Certain definitions used in the specification are provided below. Also in the examples that follow, a number of terms are used. In order to provide a clear and consistent understanding of the specification and claims, including the scope to be given such terms, the following definitions are provided.
Aiming, aim, aimed—this refers to the orientation of a device relative some reference, e.g., some known axis projecting from an output side of the device relative to a known coordinate system. For example, the aiming axis of a device such as a lighting fixture, or radio transmitter is generally established by the manufacturer and will typically align with a geometric feature of the device, but is not limited to such.
Device(s)—apparatus(es) that are to be installed at relatively precise pre-determined aiming.
Optical motion capture system—this refers to the system that tracks the position of markers added to or associated with a device and determines the position and orientation of the device. Optical motion capture systems, sometimes referred to as MOCAP in the art, can be based on passive or active markers. An optical component, such as a video camera, captures the markers in its field(s) of view (camera space). A software component tracks the markers in camera space and provides position feedback which correlates camera space position and orientation to real space. In some cases, multiple cameras are required to provide full range of motion and/or sufficient degrees of freedom of movement information. Optional motion capture systems may also be described as a dynamic measuring system. Optional motion capture systems are commercially offered by a variety of sources. A few examples are: Meta Motion of 268 Bush St. #1, San Francisco, Calif. 94104, USA, see www.metamotion.com, or NDI (Northern Digital, Inc.) of 103 Randall Drive, Waterloo, Ontario CANADA N2V 1C5, see www.ndigital.com.
Marker(s)—also known in the art as targets, optical targets, active markers, passive marker(s), or optical marker(s). Markers are features or targets used by the position sensors of an optical motion capture system to determine the position and orientation of the device they are mounted to or associated with. Markers are generally mounted on a frame, sometimes called a rigid body. Different types of markers can be used to fit the individual needs of the tracking system or device to be measured or aligned. The markers may be what are called active markers that emit a signal to the position sensor, such as an infrared signal or strobed or pulsed light, such as LEDs. What are called passive markers are retro-reflective and reflect a signal back to its emitter to indicate the position.
Rigid body(ies)—a rigid body is known in physics as a solid body of finite size having a constant distance between any two given points. For purposes of this description, a rigid body has similar meaning. The rigid body is the frame, fixture, or jig that the markers or targets mount to at a known relationship and constant distance from each other and other known points on the frame, fixture, or jig. The position and orientation of a rigid body can be determined by the known points, generally six parameters or more.
Position sensor—an apparatus that can automatically sense a device within the apparatus' effective range and translate the sensing into a position related to a reference in real space. An optical motion capture system is one example of a position sensor.
Target area—the boundary or surface area in which the aiming of a light or other aimed device is intended to be directed. For lighting, it may also be referred to or known in the art as target lighting area, lighting area, illuminated area, area to be illuminated, field, sports field or variations thereof. Some examples of target areas for aimed lighting devices are parking lots, traveled surfaces, and sports fields such as baseball, soccer or football. For non-lighting devices, such as antennas, the target area may be the acceptance angle of the aimed device or area of coverage.
Alignment beam—a beam of light produced by a light source or light that has been altered by a lens or other method into an output pattern that is at least substantially collimated or pseudo-collimated in at least one plane, but which may or may not diverge in other planes. A collimated light beam is generally described as non-diverging, or does not increase in width as distance from light source increases. The light pattern from the alignment beam, when projected onto a surface (e.g. the target area), can be shaped to produce a single dot, a line that diverges in one direction, crosshairs, concentric circles, squares or other shapes. See http://stockeryale.com/i/laser/products/snf.htm for more information about laser beams.
Pole—a pole generally refers to an elongated tube or member that supports and elevates one or more aimed device(s). Poles are not limited to round-in-cross section or cylindrical shapes. For example, square, rectangular or even triangular or oval cross sections are common. In addition, poles may vary in size, height and/or taper from larger to smaller cross section as elevation increases.
Elevating structure—a tower or other elevating structure that provides similar function as a pole.
Landmark—this refers to a point, existing or otherwise on or near the target area. The landmark can be a pre-existing, fixed, object at or on the target area or simply an easy-to-determine location or point. An example would be a home base or home base location on a baseball or softball field. Another example would be a vertical leg of a goal on a football or soccer field. Yet another example may be the center of the field. A further example would be a corner edge of a building, an edge of a roadway, or other identifiable feature.